Background: Heterozygosity for a mutation in the coagulation factor V gene (factor V Leiden; FVL) leads to resistance to activated protein C and represents the most common cause of inherited thrombophilia. FVL is associated with a high risk for thromboembolic events and might be a risk factor for venous thrombosis and early graft loss in renal transplant recipients.
Methods: We studied a cohort of 202 renal allograft recipients to assess the impact of the FVL mutation on thrombotic events and graft loss within 1 year after transplantation. We recorded the occurrence of deep venous thrombosis, pulmonary embolism, early graft perfusion defect, and graft loss. The occurrence of these events was then correlated with the presence or absence of heterozygosity for the FVL mutation.
Results: Heterozygosity for FVL was detected in 8 (4%) of 202 patients. The incidence of deep venous thrombosis or pulmonary embolism was higher in heterozygous compared with wild-type patients (25% vs. 5.7%, P=0.09). Furthermore, early graft perfusion defect (25% vs. 2.6%; P=0.03) and graft loss within 7 days after transplantation (2/8 vs. 1/194; P=0.004) were significantly more frequent among heterozygous carriers of FVL. All eight FVL carriers were negative for protein C or S deficiency and antiphospholipid and anticardiolipin antibodies, and were not carriers of the G20210A prothrombin mutation.
Conclusions: Heterozygosity for the FVL mutation predisposes renal allograft recipients to venous thromboembolic complications, graft perfusion defects, and early transplant loss. Screening for the FVL mutation and appropriate peri- and postoperative anticoagulation after renal transplantation might prevent these thromboembolic complications.